IL6 and Patent ductus arteriosus: Similarly, high levels of inflammatory markers in the umbilical cord, including IL-6, -8, -10, -12, growth/differentiation factor 15 (GDF-15), monocyte chemoattractant protein-1 (MCP-1/CCL2), and macrophage inflammatory protein-1α (MIP-1α/CCL3), were associated with the development and persistence of PDA [53,79].